Stuffing box



Dec. 23, 1941.

J. l STEPHENS ETAL STUFFING BOX Filed Jan. 29, 1940 2 Sheets-Sheet l 7 J Y a 2/ Z I hr 4 I l ATTOR Y 3, 19 J. F. STEPHENS HAL 2,266,935

' STUFFTNG 159x Filed Jan. 29, 1940 2 Sheets-Sheet 2 Patented Dec. 23, 1941 STUFFING BOX Joseph F. Stephens and Virgil F. Halliburton, Kansas City, Mo., assignors to Gustin-Bacon Manufacturing Company, Kansas City, Mo., a corporation of Missouri Application January 29, 1940, Serial No. 316,090

2 Claims.

Our invention relates to stufiing boxes and more particularly to a stufing box adapted for use in connection with packing off the pumping rod in the pumping of oil wells.

The well is usually provided with a casing through which passes the eduction tubing which carries oil out of the well. Within the tubing, or in some wells not equipped with tubing, within the casing, a long string of rods known as sucker rods are employed and these transmit the reciprocations of the Walking beam to the pump positioned in the well. The sucker rod string is secured at its upper end to a short rod known as the polish rod, which in turn is secured to the walking beam. Since pressure exists within the tubing or casing as a result of the operation of the pump against a hydrostatic head or as a result of gas within the well, or a combination thereof, itbecomes necessary in order to properly direct the discharge, to seal off the pressure within the casing or tubing. This is accomplished by the stuffing box which is screwed to the casing or tubing or an extension thereof and through which the polish rod'passes. Since oil contains quantities of fine sand, grit, and other abrasive, the packing in the stuffing box must be frequently replaced. Since the packing wears rapidly, in order to provide a tight seal, it is common in the art to provide means for feeding packing to or within the stuffing box to compensate for the wear and endeavor to maintain a tight seal. After the packingmembers in the stufiing box have become worn, it becomes necessary to replace them. r I

One object of our invention is to provide a novel stufiing box for oil wells in which the packing may be conveniently and expeditiously replaced.

Another object of our invention is toprovide a novel stuffing box for oil wells in which the packing can be fed within the stufiing box to sealing position to compensate for wear.

Another object of our invention is to provide a novel stufiing box in which the wear on the packing members is minimized, whereby the packing will have long life.

Another object of our invention is to provide a novel stufiing box in which the packing may be replaced without interrupting the seal between polish rod and casing or tubing.

Other and further objects of our invention will appear from the following description.

In the accompanying drawings which form part of the instant specification and are to be read in conjunction therewith and in which like refer- 55 is adapted to be pivoted to its dotted line posi-j ence numerals are used to indicate like parts in the various views;

Figure 1 is a perspective view of a stufiing box showing one embodiment of our invention and showing the cover of our stufiing box in raised position, in dotted lines.

Figure 2 is a sectional elevation of the stufling box shown in Figure 1.

Figure 3 is a top plan view of the stufiingbox shown in Figure 1, with the cover removed.

Figure 4 is a fragmentary perspective exploded view of the packing members and followers.

Figure 5 is an elevation with parts in section, showing a double stufiing box embodying our invention.

Referring now to the drawings, the stumng box may be secured to the well casing or tubing or an extension of the well casing or tubing indicated by the reference numeral I, by means of an externally threaded nipple 2 formed integral with the body 3 of the stuffing box. The stuffing box is provided with a cover 4, which may be secured to the body 3 by any suitable means, as for example, by threaded studs 5 and nuts 6. The cover 4 is formed with a reservoir 6, adapted to-contain a suitable lubricantwhich may be inserted through opening 8. A wiper or packing ring 9 is housed in the upper portion of the cover and secured in place by'a plate II] by stud bolts I I. The wiper ring 9 is adapted'to wipe the polish rod I2 so that lubricant contained in the reservoir I will not escape therefrom. The side walls of the body 3 are tapped for'the reception of feeding screws I3, the ends of which are formed with hexagonal portions I4, which are bored to receive crank arms I 5 slidably positioned therein.

For packing members, we prefer to use the intermeshed rubber packing members shown in Figure 4, so that as the packing members wear, the feed screws I3 may be operated to maintain the seal around the polish rod I2. Follower members I 6 are removably positioned over the ends of the feeding screws I3, as can readily be seen by reference to Figure 2. Each follower I6 is provided with a reentrant portion I 'I, adapted to fit over the button flange end I I of the feeding screw I3. The packing members I8 are provided with intermeshing fingers l9 and grooves 20, adapted to interfit as shown in Figure and are formed with curved portions 2| adapted to embrace the rod to be packed. A bail 2'2 is pivoted externally of the stufiing box and normally rests upon a ledge 23, formed integral with the stufiing box. When the cover 4 is lifted, the bail tion in Figure 1 to support the cover 4 in raised position as shown. This enables us to readily replace the packing elements when they are worn.

Normally, considerable pressure must be exerted by the feeding screws 13 in order to obtain a tight seal around the polish rod l2. It will be apparent that the wear of the packing members is a function of the abrasiveness of the fluid being packed and the polish rod, together with the pressure with which the packing members are seated against the polish rod. In the ordinary stuffing boxes of the prior art, this pressure is considerable, especially when a tight seal is desired, as is the case in oil wells where there is considerable gas pressure. An oil well is not pumped if the gas pressure is sufficient to cause it to flow but, after the gas pressure of the oil field drops to a predetermined point, that is less than the hydrostatic head of a column of oil in the well, then it is necessary to pump oil from the well. While this gas pressure is not sufiicient to lift. the column of oil, it nevertheless exercises pressure tending to cause; the oil to flow out of the stufiing box between. the packing and the polish rod. It is a salient feature of. our invention to provide astuffing box in which a minimized pressure of seating the. packing members against. the. polish rod may be employed and yet maintain atight seal.

Referring now to Figure 2, it will be observed thattherfloor 2.4 of the stuffing boxis provided with an annular raised portion 25. Similarly, the under side 26 of the cover is provided with any annular raised portion 2'1, projecting downwardly into the stufling box. The arrangement is such that the annular portions 25 and 21 will compress the. rubber in. a direction extending axfolly of the polish. rod 12-.

Referring now to Figure 3; it will be observed that; the. side walls 28 of the interior of the stufiing box. are; provided with plateaus or raised portions: 29 extending the full height of the side walls adjacent the curved portions 2|, that is, centrally of the box. These plateaus 29 will compress the packing members It in a direction transversely to the; axis of the polish rod. The feeding screws t3 exert a force at right angles to the polish rod and, longitudinally of the stuffing box, It will be seen that the pressure exerted by the feeding screws [13, acting with the raised portions 24, 21 and. 29 will compress the packing members cally around the polish rod in three directions, namely at right angles to each other, in a horizontal plane, and in a direction axially of the. polish rod. Furthermore, the projections 25 and 21- cause theintermeshing fingers L9 to seal more stronglyonone another. The result of the arrangement is that an efficient seal is obtained with but a fraction of the pressure exerted by the feeding screws than has been heretofore possible. Inthe prior art, it was necessary to compress the packing members sufliciently strongly to cause themrto expand in a direction axially of the polish rod and at right angles to the direction of the thrust exerted by the feeding screws, a suificient amount to cause the upper and: lower portions of the packing members-to seal against the floor and roof" of the. stufiing' box. If this were not done, oil would escape into the stuffing box behind the packing members and frequently out of the stuffing box past the feeding screws in their tapped holes. Furthermore, unless the seal between the body of the stufiing box and its cover 4 were tight, oil would escape between the jointithere formed. This would necessitate the use of a gasket between the cover of the stuffing box and the. body thereof, or the use of a ground joint. With our arrangement, the packing members readily seal the polish rod so that no oil escapes into the body of the stuffing box and no oil passes between the packing members and the polish rod upwardly and out of the stufiing box. The seal, furthermore, may be readily obtained with a greatly lessened pressure exerted by the feeding screw with the result that the packing members l8 will wear at a greatly decreased rate. This represents a considerable saving as well as enabling us to avoid stopping pumping operations to replace packing members, frequently.

When it is necessary to replace packing members, they may be replaced expeditiously and conveniently by merely removing the cover, supporting it in the position shown in Figure 1, backing off the. feeding screws, removing the old wornout packing members and replacing them with new packing members.

In those wells in which there is considerable gas pressure; the double stufiing box arrangement shown in Figure 5 may be employed. Normally, the lower feedingw screws iii are backed off so that the: packing members ll!" of the lower boxcontact the polish rod very lightly or not at all. In other words, the lower packing members 1.8 do not serve any packing function when the compound stuffing; box is in operation. The upper packing members 18 perform the packing function when the box is in use. When it is necessary to replace the packing members [8 in the upper portion of the stuffing box assembly, the cover 4 is not removed until the lower packing members I8 are moved into packing position by the feeding screws L3. This packs the well so that the gas or fluid pressure within the casing- I- will not escape when the cover 4 of the upper portion of the stufling box is removed. Thepacking rubbers It may be replaced, the cover 4 resecured, and the packing moved to packing position by the operation of the feeding screws l3. Then the lower feeding screws l3 are backed off to release the pressure upon the lower packing members it and the pumping rods may again be reciprocated to pump oil out of the well.

It will be seen that We have accomplished the objects ofv our invention. We have provided a stuifing box which will form an efficient and uniform sealing around the polish rod of an oil well pumping assembly and prevent the loss of gas and oil from the well. We have provided an arrangement in which the packing members may be fed to compensate for wear and one in which, bymeans of our invention, a minimized pressure may be exerted on the packing members and yet maintain the desired seal. This enables us to employ packing members for a longer period than would otherwise be possible.

Our arrangement is such that the packing members may be readily and conveniently replaced when they are wornout.

Our compound stufiing box enables-us to replace packing on wells having a considerable gas or fluid pressure without losing gas from the well or allowing oil to flow out of the well.

While we have shown two plateaus. 29 for decreasing the transverse dimension internally of the stufiing box in a direction at rig-ht angles to the movement of the packing members, it is to be understood that a single plateau, may be used to decrease the dimension locally adjacent the rod to be packed. Similarly, while we have shown two raised portions 25 and 2!- for decreas ing the internal dimension of. the box in a rc' gion adjacent the rod to be packed axially of the rod, a single raised portion 25 or 21 may be used with sufiicient height to decrease the dimension the desired amount. Likewise, the raised portion need not be made integral with p the floor or cover of the stufiing box.

It will be understood that certain features and sub-combinations are of utility and may be employed without reference to other features and sub-combinations. This is contemplated by and is within the scope of our claims. It is further obvious that various changes may be made in details within the scope of our claims without departing from the spirit of our invention. It is, therefore, to be understood that our invention is not to be limited to the specific details shown and described.

Having thus described our invention, we claim:

1. A stufiing box for packing a rod, including in combination a body member and a cover, said body member and cover being formed with aligned openings for the passage of said rod, a pair of packing members within said body member adapted to embrace the rod to be packed, means for moving said packing members into contact with the rod to be packed, the upper and lower enclosing surfaces of the body member contacting the upper and lower surfaces of the packing member adjacent the rod and shaped to form an enlarged chamber out of contact with the packing members remote from the rod.

2. A stufling box including in combination a body member, a cover for said body member forming a stuffing box therewith, said cover member and body member being formed with aligned openings for the passage of a'rod, replaceable packing members within said stufiing box, means for moving said packing members into contact with the rod to be packed, means for removably securing said cover to said body member, a bail hingedly secured to said body member, said bail being movable into contact with the rod to form a support for said cover member when in a raised position to replace said packing members.

JOSEPH F. STEPHENS. VIRGIL F. HALLIBURTON. 

